The present invention generally relates to an expandable wheel for supporting an endless abrasive belt. The present invention relates more particularly to an expandable wheel for supporting an endless abrasive belt, which includes a hub having an axis and a plurality of wheel segments engaged with the hub, where the hub and the plurality of wheel segments are adapted to rotate about the axis, and where the plurality of wheel segments are movable between a first radial position and a second radial position.
Various types of wheels are known for supporting endless abrasive belts. As these wheels are rotated, a work piece may be pushed against the exposed face of the abrasive belt in the area where the belt is supported by the wheel to abrade material from the surface of the work piece. For example, U.S. Pat. No. 528,534, xe2x80x9cExpanding Cylinder for Polishing Machines,xe2x80x9d (Evarts), describes an expandable cylinder, where the surface of the cylinder includes four staves, where two of the staves are immovably supported and the other two staves are movably supported. The movable staves move in an inward direction and through this movement, obtain the contraction desirable for putting the sandpaper on the cylinder. The movable staves are also adapted to be expanded to tighten the sandpaper around the cylinder.
U.S. Pat. No. 1,885,452, xe2x80x9cAbrading, Buffing, or Polishing Drum,xe2x80x9d (Kuhne), describes an expandable drum adapted to receive an endless cylinder of abrasive material. The drum comprises a plurality of sections mounted on a central hub, which may be secured upon a drive shaft. The hub is provided with outwardly projecting apertured lugs or eyes upon which the sections are pivoted by means of shafts extending through the lugs and through inwardly extended apertured lugs or eyes on drum sections. The free ends of each drum section are provided with inwardly projecting hooks arranged to engage with corresponding outwardly extending hooks on the hub. The hooks are undercut so that the centrifugal force developed by rotation of the drums tends to hold the hooks in engagement. The drum expanding devices comprise eccentrics on shafts cooperating with the ends of outwardly projecting lugs on the hub and with the rear faces of the hooks to expand the drum. The eccentrics are self-locking between the faces to hold the drum expanded. The drum sections are of such length that sufficient spaces may be provided to permit the required contraction of the drum and the plates are secured to each section so as to overlie the spaces and complete the periphery of the drum.
U.S. Pat. No. 3,337,998, xe2x80x9cRotary Sharpeners,xe2x80x9d (Greenfogel), describes a sharpener for a knife blade edge. The sharpener includes an arbor adapted to be mounted on its rotary support and a pair of complementary members connected to the arbor. One of the members is fixed to the arbor and the other member is connected to the arbor in a floating relationship relative to the fixed member. The sharpener also includes a means, such as a spring, for resiliently biasing the members for movement away from one another. An endless abrasive band is placed around the complementary members to define a circular abrading surface for engaging a cutting edge during the sharpening operation. The resilient means maintains the members biased against the inner circumference of the endless band to detachably secure it to the members by friction.
U.S. Pat. No. 5,117,592, xe2x80x9cApparatus and Method for Abrasive Strip Mounting,xe2x80x9d (Preston), describes a rotatable wheel for removing material from a work-piece. The circumferential surface of the wheel has a transverse slot extending into a cavity within the wheel, which is generally covered by a coverplate secured over the cavity. Within the cavity is a first device for engaging the leading end of the strip and a second device for engaging the trailing end of the abrasive strip. The first device includes a positioner that is operable to align the first device under an opening in the coverplate to permit insertion or removal of the leading end of the strip. Similarly, the second device includes a locator arm that is operable to align the second device under an opening in the coverplate to permit insertion or removal of the trailing end of the abrasive strip. The first device places static tension on the strip, while the second device places dynamic tension on the strip as the wheel is rotated.
U.S. Pat. No. 5,339,570, xe2x80x9cContact Wheel,xe2x80x9d (Amundson et al.), describes a contact wheel, which comprises an annular support portion having external surfaces and a generally cylindrical peripheral surface. The peripheral surface has spaced edges each adjoining an adjacent external surface and circumferentially spaced elongate grooves formed therein with land portions disposed between the grooves. The grooves are spaced from the respective adjacent edges of the peripheral surface to provide annular land surfaces at each of the peripheral surface. The contact wheel further includes one or more passageways formed therein, which communicate with a groove at a first end of the passageway, and with either an external surface of the annular support portion, or an adjacent groove at a second end of the passageway. The passageways aid in reducing the amount of noise generated by the contact wheel when it is rotated with the abrasive belt entrained thereover.
One aspect of the present invention provides an expandable wheel for supporting an endless abrasive belt. The expandable wheel comprises: a) a hub, including an axis; and b) a wheel segment engaged with the hub, where the hub and the wheel segment are adapted to rotate about the axis, where the plurality of wheel segment is moveable between a first radial position and a second radial position, where the first radial position is located at a first radius from the axis, where the second radial position is located at a second radius from the axis, where the first radius is less than the second radius, where the wheel segment includes a peripheral surface for supporting an endless abrasive belt, and where the peripheral surface includes a first oblique edge and a second oblique edge opposite the first oblique edge, and where the first oblique edge and the second oblique edge are oblique to the direction of wheel rotation. In another aspect of this embodiment, the expandable wheel further comprises a plurality of wheel segments engaged with the hub, where the hub and the plurality of wheel segments are adapted to rotate about the axis, where the plurality of wheel segments are moveable between the first radial position and the second radial position, and where each of the plurality of wheel segments includes the peripheral surface for supporting an endless abrasive belt. In another aspect of this embodiment, when the wheel segments are in the second radial position, the first oblique edge of a first wheel segment of the plurality of wheel segments is spaced apart from the second oblique edge of a second wheel segment of the plurality of wheel segments.
In another preferred embodiment of the above expandable wheel, each of the plurality of wheel segments include a first oblique side surface extending from the first oblique edge, a second oblique side surface extending from the second oblique edge opposite the first oblique side surface, and the peripheral surface extending between the first oblique side surface and the second oblique side surface. In another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of a second wheel segment of the plurality of wheel segments. In yet another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of the first wheel segment.
In another preferred embodiment of the above expandable wheel, the hub includes a mechanical stop, where the mechanical stop prevents the wheel segment from radially expanding beyond the second radial position.
In yet another preferred embodiment of the above expandable wheel, the expandable wheel further comprises a means for moving the plurality of wheel segments between the first radial position and the second radial position. In another aspect of this embodiment, the means for moving the plurality of segments is rotatable between a first circumferential position and a second circumferential position, where when the means is in the first circumferential position, the plurality of wheel segments are in the first radial position, and where when the means is in the second circumferential position, the plurality of wheel segments are in the second radial position. In another aspect of this embodiment, the means for moving the plurality of wheel segments comprises a cam engaged with the hub, where the cam includes slots, where each of slots include a first radial end and a second radial end opposite the first radial end, where the first radial end is located at a first radius from the axis, where the second radial end is located at a second radius from the axis, where the first radius is less than the second radius, and cam followers attached to the wheel segments, where the cam followers are slideably engaged with the cam slots. In yet another aspect of this embodiment, the means for moving the plurality of wheel segments moves all of the plurality of wheel segments simultaneously between the first radial position and the second radial position.
Another aspect of the present invention provides an alternative expandable wheel for supporting an endless abrasive belt. The expandable wheel comprises: a) a hub, including an axis; b) a wheel segment engaged with the hub, where the hub and the wheel segment is adapted to rotate about the axis, where the wheel segment is moveable from a first radial position to a second radial position, where the first position is at located at a first radius from the axis, where the second position is located at a second radius from the axis, where the first radius is less than the second radius, where the wheel segment includes a peripheral surface for supporting an endless abrasive belt; c) a mechanical stop engaged with the hub, where the mechanical stop prevents the plurality of wheel segments from expanding beyond the second radial position; and d) means for simultaneously moving the plurality of wheel segments between the first radial position and the second radial position. In another aspect of this embodiment, the expandable wheel further comprises a plurality of wheel segments engaged with the hub, where the hub and the plurality of wheel segments are adapted to rotate about the axis, where the plurality of wheel segments are moveable between the first radial position and the second radial position, and where each of the plurality of wheel segments includes the peripheral surface for supporting an endless abrasive belt.
In another preferred embodiment of the above expandable wheel, each of the peripheral surfaces includes a first oblique edge and a second oblique edge opposite the first oblique edge, and where the first oblique edge and the second oblique edge are oblique to the direction of wheel rotation.
In yet another preferred embodiment of the above expandable wheel, each of the plurality of wheel segments include a first oblique side surface extending from the first oblique edge, a second oblique side surface extending from the second oblique edge opposite the first oblique side surface, and the peripheral surface extending between the first oblique side surface and the second oblique side surface. In another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of a second wheel segment of the plurality of wheel segments. In yet another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of the first wheel segment.
In another preferred embodiment of the above expandable wheel, when the wheel segments are in the second radial position, the first oblique edge of a first wheel segment of the plurality of wheel segments is spaced apart from the second oblique edge of a second wheel segment of the plurality of wheel segments.
In yet another preferred embodiment of the above expandable wheel, the means for simultaneously moving the plurality of wheel segments is rotatable between a first circumferential position and a second circumferential position, where when the means is in the first circumferential position, the plurality of segments are in the first radial position, and where when the means is in the second circumferential position, the plurality of segments are in the second radial position. In another aspect of this embodiment, the means for simultaneously moving the plurality of wheel comprises: i) a cam engaged with the hub, where the cam includes slots, where each of slots include a first radial end and a second radial end opposite the first radial end, where the first radial end is located at a first radius from the axis, where the second radial end is located at a second radius from the axis, where the first radius is less than the second radius; and ii) cam followers attached to the wheel segments, where the cam followers are slideably engaged with the cam slots.
Another aspect of the present invention provides yet another alternative expandable wheel for supporting an endless abrasive belt. The expandable wheel comprises: a) a hub, including an axis; b) a plurality of wheel segments engaged with the hub, where the hub and the plurality of wheel segments are adapted to rotate about the axis, where the plurality of wheel segments are moveable between a first radial position and a second radial position, where the first position is at located at a first radius from the axis, where the second position is located at a second radius from the axis, where the first radius is less than the second radius, and where each of the plurality of wheel segments includes a peripheral surface for supporting an endless abrasive belt; and c) means for simultaneously moving the plurality of wheel segments between the first radial position and the second radial position, where the means for moving the plurality of wheel segments is rotatable from a first circumferential position to a second circumferential position without significant axial travel, and where when the means for simultaneously moving the plurality of wheel segments is in the first circumferential position, the plurality of wheel segments are in the first radial position, and where when the means for simultaneously moving the plurality of wheel segments is in the second circumferential position, the plurality of wheel segments are in the second radial position.
In one preferred embodiment of the above expandable wheel, each of the peripheral surfaces include a first oblique edge and a second oblique edge opposite the first oblique edge, and where the first oblique edge and the second oblique edge are oblique to the direction of wheel rotation. In another aspect of this embodiment, each of the plurality of wheel segments include a first oblique side surface extending from the first oblique edge, a second oblique side surface extending from the second oblique edge opposite the first oblique side surface, and the peripheral surface extending between the first oblique side surface and the second oblique side surface. In another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of a second wheel segment of the plurality of wheel segments. In yet another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of the first wheel segment.
In another preferred embodiment of the above expandable wheel, when the plurality wheel segments are in the second radial position, the first oblique edge of a first wheel segment of the plurality of wheel segments is spaced apart from the second oblique edge of a second wheel segment of the plurality of wheel segments.
In another preferred embodiment of the above expandable wheel, the hub includes a mechanical stop, where the mechanical stop prevents the plurality of wheel segments from radially expanding beyond the second radial position.
In yet another preferred embodiment of the above expandable wheel, the means for simultaneously moving the plurality of wheel segments comprises: i) a cam engaged with the hub, where the cam includes slots, where the each of slots include a first radial end and a second radial end opposite the first radial end, where the first radial end is located at a first radius from the axis, where the second radial end is located at a second radius from the axis, where the first radius is less than the second radius; and ii) cam followers attached to the wheel segments, where the cam followers are slideably engaged with the cam slots.
Another aspect of the present invention provides yet another alternative expandable wheel for supporting an endless abrasive belt, comprising: a) a hub, including an axis; b) a plurality of wheel segments engaged with the hub, where the hub and the plurality of wheel segments are adapted to rotate about the axis, where the plurality of wheel segments are moveable between a first radial position and a second radial position, where the first position is at located at a first radius from the axis, where the second position is located at a second radius from the axis, where the first radius is less than the second radius, and where each of the plurality of segments includes a peripheral surface for supporting an endless abrasive belt; and c) means for simultaneously moving the wheel segments between the first radial position and the second radial position.
In one preferred embodiment of the above expandable wheel, each of the peripheral surfaces includes a first oblique edge and a second oblique edge opposite the first oblique edge, and where the first oblique edge and the second oblique edge are oblique to the direction of wheel rotation.
In another preferred embodiment of the above expandable wheel, the plurality of wheel segments include a first oblique side surface extending from the first oblique edge, a second oblique side surface extending from the second oblique edge opposite the first oblique side surface, and the peripheral surface extending between the first oblique side surface and the second oblique side surface. In another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of a second wheel segment of the plurality of wheel segments. In yet another aspect of this embodiment, the first oblique side surface of a first wheel segment of the plurality of wheel segments is parallel with the second oblique side surface of the first wheel segment.
In another preferred embodiment of the above expandable wheel, when the plurality of wheel segments are in the second radial position, the first oblique edge of a first wheel segment of the plurality of wheel segments is spaced apart from the second oblique edge of a second wheel segment of the plurality of wheel segments.
In another preferred embodiment of the above expandable wheel, the hub includes a mechanical stop, where the mechanical stop prevents the plurality of wheel segments from radially expanding beyond the second radial position.
In yet another preferred embodiment of the above expandable wheel, the means for simultaneously moving the plurality of segments is rotatable between a first circumferential position and a second circumferential position, and where when the means is in the first circumferential position, the plurality of segments are in the first radial position, where when the means is in the second circumferential position, the plurality wheel of segments are in the second radial position. In another aspect of this embodiment, the means for simultaneously moving the plurality of wheel comprises: i) a cam engaged with the hub, where the cam includes slots, where the each of slots include a first radial end and a second radial end opposite the first radial end, where the first radial end is located at a first radius from the axis, where the second radial end is located at a second radius from the axis, where the first radius is less than the second radius; and ii) cam followers attached to the wheel segments, where the cam followers are slideably engaged with the cam slots.
Another aspect of the present invention provides another alternative expandable wheel for supporting an endless abrasive belt. The expandable wheel comprises: a) a hub, including an axis; b) a plurality of wheel segments engaged with the hub, where the hub and the plurality of wheel segments are adapted to rotate about the axis, where the plurality of wheel segments are moveable from a first radial position to a second radial position, where the first position is at located at a first radius from the axis, where the second position is located at a second radius from the axis, where the first radius is less than the second radius, where each of the plurality of wheel segments includes a peripheral surface for supporting an endless abrasive belt; c) a mechanical stop engaged with the hub, where the mechanical stop prevents the plurality of wheel segments from expanding beyond the second radial position; d) a cam engaged with the hub, where the cam includes slots, where the each of slots include a first radial end and a second radial end opposite the first radial end, where the first radial end is located at a first radius from the axis, where the second radial end is located at a second radius from the axis, where the first radius is less than the second radius; and e) cam followers attached to the wheel segments, where the cam followers are slideably engaged with the cam slots.
Another aspect of the present invention provides an alternative expandable wheel for supporting an endless abrasive belt. The expandable wheel comprises: a) a hub, including an axis; b) a plurality of wheel segments engaged with the hub, where the hub and the plurality of wheel segments are adapted to rotate about the axis, where the plurality of wheel segments are moveable between a first radial position and a second radial position, where the first position is at located at a first radius from the axis, where the second position is located at a second radius from the axis, where the first radius is less than the second radius, and where each of the plurality of segments includes a peripheral surface for supporting an endless abrasive belt; c) a cam engaged with the hub, where the cam includes slots, where the each of slots include a first radial end and a second radial end opposite the first radial end, where the first radial end is located at a first radius from the axis, where the second radial end is located at a second radius from the axis, where the first radius is less than the second radius; and d) cam followers attached to the wheel segments, where the cam followers are slideably engaged with the cam slots.